Apparatus for making metal cases from tubular pieces



Allg i0, 1.937- o. BIGINELLI y 2,089,912

APPARATUS FOR MAKING METAL CASES FROM TUBULAR PIECES Filed March 31, 1936 2 Sheng-sheet 1 En' Q@ LC o i I X mm W5/V70@ 0165s TE Bmw/sal Hrw/@Mfrs Aug? 1.0, 1937 'I o. BIGINELLI y2,089,912

APPARATUS -FOR MAKINGMETAL CASES FROM TUBULAR PIECES Filed March s1, 193e 2 sheets-sham 2 \I N n 1 M x Y V '/l o c I Q Q Patented Aug. 10, 1937v PATENT GFFICE APPARATUS FOR MAKING METAL CASES FROM TUBULAR PIECES Oreste Biginelli, Clermont-Ferrand, France Application March 31, 1936, Serial No. 71,884 'In France May 23, 1935 2 Claims.

In a previous patent I have described a process for the manufacturing of metal cases from a tubular piece in which one of the principal stages in the manufacturing process consists .in shap- 5 ing the bottom of the case by the spinning of the metal at one end of the tube between a stationary counter-punch and a movable punch, the tube being surrounded at the point where the bottom is to be produced by a die which rotates relatively to the whole of the system. Under the combined action of the heat produced by the friction of the rotary die and of the pressure of the movable punch the metal is spun in a solid bottom taking the shape of the space provided between the die, the stationary counterpunch and the movable punch at the end of the stroke of the latter.

The present invention has for its object a particular mode of producing the bottom of the case which differs from the one described in the above patent in that a stationary die is substituted for the rotary die, said stationary die being exposed to the action of a source of heat so as to be heated to a temperature suiciently high to practically heat the metal of the tube in the region where the bottom is formed. The process of shaping of the bottom differs therefore from that described in the aforesaid patent, in that the supply of heat is realized by direct conductivity instead of being produced by the friction of a rotary die.

The appended drawings show by way of example an apparatus which allows the working of the process thus modified as appliedto the manufacture of a cartridge case.

Fig. 1 shows the parts in the position that they occupy at the beginning of the operation. Fig. 2 illustrates the same partsl at the end of the operation. The apparatus for the execution of the process according to the present invention is mounted between the two ends of a double acting press. It comprises substantially: a punch l sliding in a' guide 2 threaded into the frame 3 of the press; a mandrel 4 sliding in a guide 5 also threaded into the frame 3, the'front end 5 of said mandrel constituting a heatingdie; a counter-punch l guided inside the mandrel 4, and, lastly a heating device which comprises the source of heat placed in the annular space 8 around the metal mass which is also ring shaped, one inner cylindrical bearing of which engages the outer portion of the end 6 ofthe mandrel 4 in order to insure the transmission of heat. The

heating element is suitably insulated by a heat (Cl. 25J-1.31)

protecting case I 0 and may itself be constituted at will by an electrical resistance, a stream of hot gases in circulation or any other suitable system. y

The mode of operation in that case is as 5 follows:

The unit comprising the mandrel 4 and the counter-punch 1 having been drawn outside the guide 5 the tubular piece is introduced in the mandrel and engaged upon the counter-punch. 10 The first stroke of the press pushes the counterpunch, the mandrel and the tube as a whole in the guide 5 up to the position indicated in Fig. 1 where it is maintained. The tubular piece then occupies the position indicated at II in 15 Fig. 1.

At the second stroke of the press, the punch l slides in the guide 2 to come in the position shown in Fig. 2. The metal of the portion of the tube which was outside the mandrel 4 is 20 thus forged and forms a solid bottom l2 having the shape of the space existing between the counter-punch 1, the punch l and the die 6. During this operation the heat from the heating element is transmitted by conductivity from rthe 25 metal mass 9 to the portion 6 of the mandrel 4, thus facilitating the forging of the metal which is designed to form the bottom of the case. The punch I is not rotated but merely reciprocatedin the guide 2. 3o

The manufactured case will be extracted after the unity consisting in the mandrel 4 and the counter-punch 'l has been taken out of the guide 5.

The present method of manufacture may be 35 used for manufacturing cases of all kinds such for example as cartridge cases, gascontainers etc.

What I claim and desire to secure by Letters Patent of the United States is: 40

1. A device for the manufacture of metal cases, more especially of cartridge cases which comprises a stationary counter-punch upon which a portion of the drawn tube utilized is engaged,

a longitudinally movable punch which is placed 45 -heating device placed around the die formed at the end of the mandrel to heat same in order 55 to bring the metal to a plastic state during the operation, and to allow the formation of a solid bottom at the endk f the tube. Y

2. A device for the manufacture of metal cases, more especially of cartridge cases which comprises a stationary counter-punch upon which a portion of the drawn tube to be treated is engaged, a longitudinally movable punch' opposite said stationary counter-punch and compris- 10 ing a specially formed head for shaping the bottom of the case, of a stationary guide surrounding the -counter-punch and the tube to be operated upon said guide being provided with an end which constitutes adie, a stationary guide around said mandrel, a heating device around said die and a ring shaped metal mass interposed between the heating .device and the die in order to ensure and regulate the heating of said die during the operation so as to render themetal plastic during the operationv and to thus allow the' formation of a solid bottom closing the end of the tube.

ORESTE BIGINELLI. 

